Portable membrane filtration

ABSTRACT

A portable filtration system is described. The system may comprise: a mixing portion, comprising: a pump adaptor and a contaminant regulator. The pump adaptor may comprise: an upper plate, a lower plate, and a screen. The screen may axially extend between the upper and lower plates, wherein the upper plate, the lower plate, and the screen define a channel of a mixing chamber. The contaminant regulator may comprise a through-passage coupled to the upper plate, wherein the through-passage is in fluid communication with the mixing chamber.

GOVERNMENT INTEREST

The invention(s) described herein may be manufactured, used, and/orlicensed by or for the Government of the United States of Americawithout payment by the Government of any royalties thereon.

TECHNICAL FIELD

The present disclosure pertains to fluid systems, and more particularlyto systems having membranes.

BACKGROUND

Reverse osmosis is a fluid purification process that uses a permeablemembrane to separate dissolved solids from potable water. Fluid that isnot potable is typically removed from the system as waste fluid.

SUMMARY

According to one non-limiting embodiment of the disclosure, a portablefiltration system is described. The system may comprise: a mixingportion that may comprise a pump adaptor and a contaminant regulator,wherein the pump adaptor may comprise: an upper plate; a lower plate,and a screen axially extending between the upper and lower plates,wherein the upper plate, the lower plate, and the screen define achannel of a mixing chamber, wherein the contaminant regulator maycomprise a through-passage coupled to the upper plate, wherein thethrough-passage is in fluid communication with the mixing chamber.

According to another non-limiting embodiment of the disclosure, aportable filtration system is described. The system may comprise: amixing portion that may comprise: a feed pump, a pump adaptor, acontaminant regulator, an output passage in fluid communication with thefeed pump, and a recycle passage in fluid communication with athrough-passage of the contaminant regulator; and a membrane portionthat may comprise: a filter, a boost pump, a membrane apparatus, aconcentrate passage, and an energy recovery apparatus. The pump adaptormay comprise: an upper plate; a lower plate, and a screen axiallyextending between the upper and lower plates, wherein the upper plate,the lower plate, the screen, and the head of the feed pump define amixing chamber. The contaminant regulator may comprise thethrough-passage which may be coupled to the upper plate, wherein thethrough-passage is in fluid communication with the mixing chamber. Themembrane apparatus may comprise a permeate chamber and a concentratechamber segregated by a membrane, wherein the membrane apparatus is influid communication with the feed pump via the filter, the boost pump,and the output passage. The concentrate passage may carry high-pressureconcentrate fluid from the concentrate chamber to the energy recoverydevice, and the recycle passage may carry low-pressure concentrate fluidto the mixing chamber via the contaminant regulator.

According to another non-limiting embodiment of the disclosure, portablefiltration system is disclosed. The system may comprise: a pump adaptor,comprising a mixing chamber, an inlet for receiving raw fluid, an inletfor receiving recycled fluid, and an outlet; a feed pump in fluidcommunication with the outlet of the pump adaptor; a boost pump in fluidcommunication with the feed pump; an energy-recovery means in fluidcommunication with the boost pump; and a membrane apparatus comprising aconcentrate chamber and a permeate chamber, wherein the concentratechamber is in fluid communication with the energy recovery means via aconcentrate passage, wherein the energy-recovery means is in fluidcommunication with the pump adaptor via a recycle passage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an embodiment of a portable filtrationsystem illustrating a membrane portion and a mixing portion.

FIG. 2 is a schematic diagram illustrating an example of a contaminantregulator.

FIG. 3 is a perspective view of an embodiment of a mixing portion.

FIG. 4 is a side view of an embodiment of a feed pump.

FIG. 5 is a perspective view of a portion of a head of the feed pumpshown in FIG. 4 .

FIG. 6 is a perspective view of the feed pump shown in FIG. 4 coupled toan embodiment of a pump adaptor.

FIG. 7 is a top view of the feed pump and pump adaptor shown in FIG. 6 .

FIG. 8 is a bottom view of the feed pump and pump adaptor shown in FIG.6 .

FIG. 9 is an exploded, perspective view of the pump adaptor shown inFIG. 6 .

FIG. 10 is a top view of the pump adaptor shown in FIG. 9 .

FIG. 11 is a side view of the pump adaptor shown in FIG. 9 .

FIG. 12 is a schematic diagram of a set of contaminant regulators, eachconfigured according to a different bleed rate parameter.

FIG. 13 is a schematic diagram illustrating another embodiment of theportable filtration system.

DETAILED DESCRIPTION

Turning now to FIG. 1 , wherein throughout the figures like referencenumerals indicate like or similar features or functions, a portablefiltration system 10 is disclosed that is used to filter fluids using amembrane. As will be described in greater detail herein and according toone embodiment, the system 10 comprises a membrane portion 12 and amixing portion 14. The mixing portion 14 may draw and pre-filter a rawfluid from an environmental body of water—e.g., such as a lake, river,puddle, etc. Thereafter, the membrane portion 12 executes a fluidfiltration process yielding a permeate fluid (e.g., potable water) and aconcentrate fluid (e.g., a fluid comprising contaminants such asparticulates, bacteria, salts, chemicals, and/or other dissolved orsuspended solids). The membrane portion 12 recycles the concentratefluid into the mixing portion 14 which then mixes the recycledconcentrate fluid with newly-drawn raw fluid. As described more below,the mixed fluids are iteratively processed via membrane portion 12resulting in a substantial increase of permeate fluid (e.g., per unitvolume of raw fluid) without clogging filter(s) of the system 10 with abuild-up of contaminants.

According to an embodiment, membrane portion 12 may comprise a filter18, a boost pump 20, an energy recovery apparatus 22, and a membraneapparatus 24. Filter 18 may receive a pre-filtered fluid from mixingportion 14 via an output passage 28. Filter 18 may be comprised of anysuitable material(s) and have any suitable shape or configuration.Filter 18 may remove contaminants smaller than those filtered by mixingportion 14—e.g., contaminants larger than 1 micro-meter (μm) may befiltered. Non-limiting examples of filter 18 include a pleated-, anelectrospun-, a string-wound-, or solid block comprised of polymericmaterials, activated charcoal, or natural polymers. Such filters areused to remove to some degree biological organisms, dissolved material,and suspended materials such as bacteria, heavy materials, and dirt.According to at least one embodiment, filter 18 may represent multiplefilters (e.g., such as illustrated filters 18 a, 18 b)—e.g., in the caseof two or more filters, the filters may be arranged in series whereinone filter is downstream of one another or according to any othersuitable arrangement (e.g., filter within a filter).

Boost pump 20 is downstream of and in fluid communication with filter18—receiving fluid therefrom via a passage 30. Boost pump 20 may be anysuitable high-pressure pump—e.g., a non-limiting example of boost pump20 may be of a positive displacement pump (e.g., non-limiting examplesincluding a rotary vane pump, a gear pump, or a piston pump) or avelocity pump (e.g., non-limiting examples including a centrifugal pumpor axial flow pump). According to an embodiment, boost pump 20 may becalibrated to increase a fluid pressure (also referred to herein as‘line pressure’) from 5 pounds-per-square inch (psi) to 200 psi.According to at least one example, boost pump 20 increases the pressureof the fluid delivered to energy recovery apparatus 22 (via a passage32) to 150±50 psi.

Energy recovery apparatus 22 may be a device that: further increasesfluid pressure to facilitate filtration via the membrane apparatus 24,captures energy from a fluid exiting the membrane apparatus 24, and usesthe captured energy to repeatedly facilitate filtration (e.g., suchreverse osmosis, nanofiltration, or the like)—thereby increasing a powerefficiency of the system 10. More particularly, energy recoveryapparatus 22 increases a fluid pressure of the fluid received viapassage 32 (via an inlet 34) and delivers this high-pressure fluid(downstream) to membrane apparatus 24 via an outlet 36 and via a passage38. Fluid that exits the membrane apparatus 24 (also under highpressure) may be received at the energy recovery apparatus 22 via aconcentrate passage 40 and via an inlet 42. And when energy recoveryapparatus 22 recaptures energy from the fluid in concentrate passage 40,energy recovery apparatus 22 may output this fluid via an outlet 44 andvia a recycle passage 46 (e.g., returning it to mixing portion 14).

Energy recovery apparatus 22 is a non-limiting example of a means forenergy recovery. According to one non-limiting embodiment, energyrecovery apparatus 22 may be a Clark pump manufactured by SpectraWatermakers, Inc. or may be as described in U.S. Pat. No. 5,628,198 or5,462,414, each of which are hereby incorporated by reference in theirrespective entireties. Thus, the Clark pump may be a pump which convertspotential energy of a fluid received via concentrate passage 40 (e.g.,under relative high pressure) to kinetic energy to increase pressure ofthe fluid in passage 38 (i.e., of fluid being delivered to membraneapparatus 24). According to a non-limiting example wherein the fluidreceived at inlet 34 is 150 psi, energy recovery apparatus 22 mayincrease the fluid pressure in passage 38 to 600-1000 psi. Continuingwith this non-limiting example, fluid pressure in concentrate passage 40may be 1-20 psi less than that delivered to the membrane apparatus 24 inpassage 38 (e.g., it may be 580-999 psi). Further continuing with thisnon-limiting example, following energy recaptured by energy recoveryapparatus 22, fluid pressure in recycle passage 46 may be 10-20 psi, andthe recaptured energy may offset power demands to pressurize the fluidin passage 38.

In at least one embodiment, the means for energy recovery is a Pearsonpump, e.g., such as that shown in International Patent PublicationWO1998022202, which is incorporated by reference herein in its entirety.In yet other examples, the means for energy recovery may include systemswhich employ more or fewer inlets, more or fewer outlets, more or fewerpassages (in or out of energy recovery apparatus 22), or a combinationthereof. Further, such examples may employ components other than pistonsand solenoids to move and recover energy from fluid under pressure.

Membrane apparatus 24 may be any suitable apparatus for filtration thatutilizes a membrane to filter fluid, wherein the fluid includes but isnot limited to water. Non-limiting examples of membrane apparatus 24include a reverse osmosis (RO) device (e.g., filtering dissolved orsuspended solids greater than 0.1 nanometers (nm)), a nanofiltrationdevice (e.g., filtering dissolved or suspended solids greater than 2-5nm), or other like device. Membrane apparatus 24 may comprise an inlet48 to a concentrate chamber 50 and an outlet 52 therefrom, a membrane 54that defines a boundary between the concentrate chamber 50 and apermeate chamber 56, wherein the permeate chamber 56 comprises an outlet58 which may empty to an optional tank 60 for storing potable fluid.Inlet 48 and concentrate chamber 50 are in fluid communication withenergy recovery apparatus 22 via passage 38, and concentrate chamber 50and outlet 52 are in fluid communication with energy recovery apparatus22 via concentrate passage 40. Membrane apparatus 24 may have otherfeatures (not shown); such features may be known by those appreciated inthe art. In operation, fluid pressure in concentrate chamber 50 may beadequately high to reverse the osmosis process thereby causing a potablefluid to be pressed through membrane 54. As such fluid is pressedthrough membrane 54, the concentration (parts per million (PPM)) of thecontaminants may increase in the concentrate chamber 50. Consequently,this fluid may be circulated to mixing portion 14 via: the concentratepassage 40, the energy recovery apparatus 22, and ultimately the recyclepassage 46. As will be discussed below, mixing portion 14 may beconfigured to regulate contaminant concentration while mixing andrecirculating at least a portion of the fluid in the recycle passage 46.

Continuing with the non-limiting example discussed above wherein fluidpressure in passage 38 may be 600-1000 psi, fluid pressure inconcentrate chamber 50 may decrease slightly as fluid permeates throughmembrane 54; e.g., fluid pressure in concentrate chamber 50 may decrease1-20 psi (e.g., decrease approximately 0.1-3.3% to 580-999 psi).Consequently, in this example, fluid pressure in concentrate passage 40may be 580-999 psi as well. Fluid pressure in permeate chamber 56 may be1-10 psi. Other examples also exist—wherein fluid pressure differs inone or more of apparatuses 22, 24 and/or passages 32, 38, 40, 46.Further, skilled artisans will appreciate that other techniques may beemployed using membrane apparatus 24.

Turning now mixing portion 14, as described above, mixing portion 14 maybe in fluid communication with membrane portion 12. Mixing portion 14may be upstream of membrane portion 12 as fluid moves from mixingportion 14 to membrane portion 12 via passage 28. And mixing portion 14also may be downstream of membrane portion 12 as fluid moves frommembrane portion 12 to mixing portion 14 via recycle passage 46.According to an embodiment, mixing portion 14 comprises a pump adaptor64, a contaminant regulator 66, and a feed pump 68.

Pump adaptor 64 may comprise a structure 70 having a hollow regiondefining a mixing chamber 72, wherein structure 72 comprises an inlet 74enabling entry of a raw fluid into mixing chamber 72, an inlet 76 influid communication with recycle passage 46 thereby enabling concentratefluid to enter mixing chamber 72, and an outlet 78 to feed pump 68.Mixing chamber 72 may be any suitable size (e.g., 100-5000 milliliters(mL)) and any suitable shape (e.g., a rectangular volume, a cylindricalvolume, a spherical volume, just to name a few examples). According toat least one embodiment, the mixing chamber 72 has a size between100-1100 mL.

Contaminant regulator 66 may be any structural device configured tobleed off at least some of the concentrate fluid to control or regulatethe concentration (PPM) of contaminants processed by the system 10.E.g., as discussed above, without contaminant regulation, an excessamount of contaminants will eventually build up and inhibit efficientoperation of the system 10. Non-limiting examples of contaminantregulator 66 include a fixed bleed-off component or a variable bleed-offcomponent. As used herein, a fixed bleed-off component may comprise acomponent comprising at least one inlet opening, a through-passage, atleast outlet opening, and one or more ports of a fixed size, wherein theat least one inlet opening is coupled to a first component of a fluidsystem (to permit fluid intake) and the at least one outlet opening iscoupled to a second component of the fluid system (to facilitate flowthereto), wherein the one or more ports permit fluid to escape the fluidsystem—e.g., in one embodiment, the one or more ports permit fluid toleak or spray into an environment outside of the system 10 (rejectedfluid), whereas fluid that moves from the at least one inlet openingthrough the through-passage and out the at least one outlet opening maybe remain within system 10 (e.g., passing from recycle passage 46 tomixing chamber 72). As used herein, a variable bleed-off component maybe similar or identical to a fixed bleed-off component except that thevariable bleed-off component further comprises one or more flow controldevices that can be used to change a size of the respectiveport(s)—e.g., in one such embodiment, the flow control device(s) may bevalves that control flow, redirection of flow through different ports orpassages (e.g., of a manifold), etc. Such flow control devices may bemanually-operated or electronically-operated.

FIG. 2 illustrates an example of contaminant regulator 66 embodied as afixed bleed-off component. According to one example, contaminantregulator 66 comprises an elongated housing 80 having a through-passage82 extending from an input opening 83 at an end 84 (coupled to recyclepassage 46) to an output opening 85 at an end 86 having aquick-disconnect (QDC) feature 88 (e.g., a spring-loaded fluidcoupling). Between ends 84, 86, bleed passages 90, 92 extend fromthrough-passage 82 to corresponding ports 94, 96 so that, duringoperation of system 10, concentrate fluid in recycle passage 46 flowsthrough the through-passage 82 (from input opening 83 to output opening85 and also through the bleed passages 90, 92 and from correspondingports 94, 96. Contaminant fluid is thereby bled from contaminantregulator 66 in a controlled manner. E.g., assuming line pressure inrecycle passage 46 is constant, contaminant fluid is bled from system 10at a fixed rate. According to this embodiment (and not intending to belimiting), a nozzle 100 may be coupled to pump adaptor 64 such thatnozzle 100 has a passage 102 that facilitates fluid communicationbetween contaminant regulator 66 and mixing chamber 72 via inlet 76.While not required in all examples, nozzle 100 may have a QDC feature104 that corresponds with QDC feature 88. In other examples, structure70 itself may comprise such a QDC feature.

The contaminant regulator 66 of FIG. 2 is a fixed bleed-off component.That is, the bleed passages, 90-92 and the ports 94, 96 are a fixedsize. Such a contaminant regulator may be selected from a set ofcontaminant regulators based upon a predetermined bleed rate, eachcontaminant regulator having differently sized bleed passages and/orports. An example of selecting contaminant regulator 66 based on bleedrate is described below.

Returning to FIG. 1 , in general, contaminant regulator 66 is in fluidcommunication with recycle passage 46 and inlet 76 (to mixing chamber72). E.g., in some embodiments, an optional passage 106 may fluidlycouple contaminant regulator 66 to inlet 76; however, in at least oneexample, contaminant regulator 66 is mechanically coupled to structure70 of pump adaptor 64 and in direct fluid communication with inlet 76.And in at least one example (as shown in FIG. 2), contaminant regulator66 is mechanically coupled to nozzle 100 and in direct fluidcommunication with inlet 76. As used herein, ‘direct fluidcommunication’ may mean there are no intermediate components throughwhich fluid may flow; correspondingly, ‘indirect fluid communication’may mean that at least one intermediate component may be located betweentwo components said to be in fluid communication. Thus, as used herein,‘fluid communication’ may refer to direct fluid communication orindirect fluid communication.

FIG. 1 also illustrates feed pump 68 in fluid communication with mixingchamber 72 via outlet 78 and a passage 110. Feed pump 68 may compriseany suitable pumping device to draw raw fluid through pump adaptor 64and deliver fluid to membrane portion 12. In at least one embodiment,feed pump 68 is a positive displacement pump; however, this is notrequired. A non-limiting commercial example of feed pump 68 is theSDS-Q-130 manufactured by Sun Pumps, Inc.

FIG. 1 also illustrates that mixing portion 14 may comprise a pre-filter111 that at least partially encloses pump adaptor 64 and feed pump 68.Pre-filter 111 may be any suitable filter that filters out largeparticles such as silt, sand, organic matter, etc. Pre-filter 111 mayhave any suitable shape and size. Further, pre-filter 111 may be made ofany suitable materials. Non-limiting examples of suitable materialinclude any suitable plastic(s), natural fiber(s), and/or paper (e.g.,fabrics, sheets, or other bags). In at least one example, pre-filter canbe removed and either cleaned or replaced with a new pre-filter shouldthe pre-filter become excessively clogged or should it deteriorate.

Thus, in operation, system 10 may draw a raw fluid through thepre-filter 111 into mixing chamber 72. Thereafter, feed pump 68 may drawfluid from mixing chamber 72 and pump it to filter 18 via passage 28.Boost pump 20 may increase the fluid pressure after the fluid passesthrough filter 18. And subsequently, energy recovery apparatus 22 mayincrease the fluid pressure additionally. Membrane apparatus 24 mayreceive this high pressure fluid from energy recovery apparatus 22 andpermeate fluid may be collected within permeate chamber 56 after suchfluid passes through membrane 54. Fluid which does not pass through themembrane 54 may exit the membrane apparatus 24, returning to energyrecovery apparatus 22 via a concentrate passage 40 and there bede-pressurized. During this process, as described above, energy recoveryapparatus 22 may use the energy recaptured during de-pressurization topower the pressurization of incoming fluid from boost pump 20. Oncede-pressurized, concentrate fluid may exit the energy recovery apparatus22 and return to the mixing portion 14 via recycle passage 46. Beforeentering mixing chamber 72 (and mixing with incoming raw fluid), someconcentrate fluid may be removed from the system 10 via contaminantregulator 66—e.g., by bleeding some of the concentrate fluid off.Determining how much to bleed off may be based on the contaminants andcontaminant PPM in the particular raw fluid, as described more below.Concentrate fluid which is not bled off passes into the mixing chamber72 and mixes with the raw fluid. Feed pump 68 thereafter may pump amixture of raw fluid and concentrate fluid. It is contemplated that thepumping of raw fluid, the mixing of concentrate fluid and raw fluid, theenergy recovery using apparatus 22, the process of reverse osmosis,nanofiltration, or the like, and the bleeding off of some of theconcentrate fluid may occur concurrently. For example, feed pump 68 maybe operating concurrently with any combination of boost pump 20, energyrecovery apparatus 22, membrane apparatus 24, and contaminant regulator66.

Turning now to FIG. 3 , an embodiment of mixing portion 14 is shown thatcomprises a feed pump 68′, a pump adaptor 64′, and a pre-filter 111′which is retained by features of the pump adaptor 68′, as describedbelow. It should be understood that this is merely one example; andother feed pump, pump adaptor, and/or pre-filter embodiments also exist.

FIGS. 4-5 illustrate a non-limiting example of feed pump 68′ having alongitudinal axis X Feed pump 68′ may comprise a body 112 and a head 114extending axially from the body 112, wherein an axial length of feedpump 68′ may be measured from an end 116 (on body 112) to an end 118 (onhead 114). Head 114 may comprise a cap 120, a collar 122, and a pumpintake 123, wherein the pump intake 123 may be defined by a cylindricalmesh ring 124 axially extending between the cap 120 and collar 122. Adiameter of mesh ring 124 may be smaller than the correspondingdiameters of cap 120 and collar 122 such that a circumferential flange126 and a circumferential flange 128, respectively, extend radiallyoutwardly from mesh ring 124.

As shown in FIGS. 3-5 , feed pump 68′ may comprise a pump mechanism 130positioned within the body 112, within the head 114, or at leastpartially within both (in this example, pump mechanism 130 is locatedwithin the head 114). A pump outlet 132 may be located at end 118 on cap120—e.g., extending axially inwardly toward pump mechanism 130 from anouter surface 134. Here, it is centrically located (coaxial with axisX); however, this is not required in all examples. Raw fluid may be incontact with an outer surface 136 of the cylindrical mesh ring 124, andthe pump mechanism 130 may draw fluid into pump intake 123 (through meshring 124), increase its fluid pressure within pump mechanism 130, andpush the pressurized fluid out of pump outlet 132.

In at least one embodiment, feed pump 68′ has an axially-extendingexternal protrusion 138 that extends radially outwardly from an outersurface 140 of the feed pump 68′ (e.g., across at least a portion ofbody 112 and head 114). Protrusion 138 may have features to retainelectrical wiring 142 which may extend from end 116 and whichelectrically powers the pump mechanism 130. In this example, wiring 142may extend axially away from end 118 (as best shown in FIG. 3 ).

Now turning to FIGS. 6-8 , an embodiment of a mixing portion 14′ isshown wherein the pump adaptor 64′ illustrated in FIG. 3 is shownmounted to feed pump 68′ (e.g., the pre-filter 111′ is hidden). FIG. 6is a perspective view, FIG. 7 is a top view, and FIG. 8 is a bottomview. As described more below, pump adaptor 64′ may be extendcircumferentially and radially outwardly from the pump intake 123 offeed pump 68′—e.g., being sandwiched between circumferential flanges126, 128 of the cap 120 and collar 122, respectively.

In accordance with FIGS. 6-8 (which show pump adaptor 64′ coupled tofeed pump 68′) and in accordance with FIGS. 9-11 (which show variousviews of pump adaptor 64′ without feed pump 68′), pump adaptor 64′ maycomprise an upper plate 150 having an annular shape, a lower plate 152also having an annular shape, and a screen 154 having a ring shape,wherein the screen 154 axially extends between the upper and lowerplates 150, 152. The upper plate 150, the lower plate 152, and thescreen 154 define a circumferential channel 156 of a mixing chamber 72′(refer to FIGS. 7-8 ). When assembled with feed pump 68′, a volume ofmixing chamber 72′ is defined by upper plate 150, lower plate 152,screen 154, and the outer surface 136 of mesh ring 124 of feed pump 68′(outer surface 136 shown in FIGS. 4-5 ).

As best shown in FIG. 9 , upper plate 150 may comprise a plurality ofcircumferentially-spaced holes 160 extending from an upper surface 162to a lower surface 164 thereof. Lower surface 164 may comprise acircumferential channel 166 (shown in phantom) inboard of an outer edge168 of the upper plate 150 that is used to retain the screen 154, asdescribed below. The outer edge 168 may define an outer diameter (OD₁₅₀)of the upper plate, and an inner edge 170 of the upper plate 150 maydefine an inner diameter (ID₁₅₀) thereof. As best shown in FIG. 9 , theinner edge 170 may comprise a key 172 having a shape which correspondswith external protrusion 138 of feed pump 68′; thus, when assembled tofeed pump 68′, key 172 may inhibit rotation of pump adaptor 64′ withrespect to feed pump 68′.

Upper plate 150 may comprise at least one inlet 76′. Inlet 76′ maycomprise a through-hole positioned between the inner and outer edges170, 168. In at least one example, an inner surface of inlet 76′ hasthreads sized to receive a nozzle 100′ which has a quick-disconnectconnector (QDC) feature 104′ (e.g., similar to that shown in FIG. 2 ).Nozzle embodiments other than that shown may be used as well. In theillustrations, a threaded second inlet is also shown (having a plug withcorresponding threads); however, this is not required.

Turning now to the lower plate as best shown in FIG. 9 , lower plate 152may comprise a plurality of circumferentially-spaced apertures 182extending from an upper surface 184 to a lower surface 186 thereof. Asecondary screen 188 may be located within each of the plurality ofapertures 182, and these secondary screens 188 may further promoteintake of raw fluid (e.g., when mixing portion 14′ is laying on itsside, and intake through screen 154 is at least partially obstructed orotherwise inhibited due to mixing portion 14′ resting in sand, silt,mud, etc.). Each secondary screen 188 may comprise similar or identicalmaterial and construction as that of screen 154, as described below.

Additionally, lower plate 152 may comprise a plurality ofcircumferentially-spaced holes 190 extending from upper surface 184 tolower surface 186. While not required, these circumferentially-spacedholes 190 may be interstitially-located between thecircumferentially-spaced apertures 182, as illustrated. On lower plate152, upper surface may comprise a circumferential channel 192 inboard ofan outer edge 194 of the lower plate 152 that also is used to retain thescreen 154, as described below. The outer edge 194 may define an outerdiameter (OD₁₅₂) of the lower plate, and an inner edge 196 of the lowerplate 152 may define an inner diameter (ID₁₅₂) thereof. Inner edge 196also may comprise a key 198 having a shape which corresponds withexternal protrusion 138, as shown in FIGS. 8-9 .

Screen 154 may comprise a ring body 200 of perforated material axiallyextending from an upper edge 202 to a lower edge 204. The material maybe mesh or the like—being suitable to filter incoming raw fluid.According to one non-limiting example, screen 154 may filter particleslarger than 0.018″ (approximately 450 μm). In at least one example, meshsize of ring body 200 may be the same as or similar to that of the meshring 124 of feed pump 68′ (e.g., within a range of 400 μm to 600 μm (or30-40 sieve size), in accordance with U.S. Sieve Size); however, this isnot required. A diameter of screen 154 may correspond withcircumferential channels 166, 192 of the upper and lower plates 150,152, respectively. Upper and lower edges 202, 204 of screen 154 may fitwithin channels 166, 192, respectively, so that the upper and lowerplates 150, 152 retain the screen 154 in place during operation.

Pump adaptor 64′ further may comprise a plurality of supports 206 whichhave an axial length that correspond with an axial length of the screen154. In at least one embodiment, each support 206 is elongated and has ablind and threaded hole at each end 208, 210. Support examples existother than those illustrated. Additionally, pump adaptor 64′ maycomprise a first set of fasteners 214 and a second set of fasteners 216.The first set of fasteners 214 may extend through each of the pluralityof circumferentially-spaced holes 160 in upper plate 150 and be threadedinto an end 208 of a respective support 206. Similarly, the second setof fasteners 216 may extend through each of the plurality ofcircumferentially-spaced holes 190 in lower plate 152 and be threadedinto an end 210 of a respective support 206. In this manner, upper andlower plates 150, 152 may be compressed toward one another withoutdamaging screen 154 as supports 206 bear the load.

Pump adaptor 64′ further may comprise an annular retention ring 220 usedto retain pre-filter 111′, as described more below. More particularly,retention ring 220 may have a plurality of circumferentially-arrangedholes 222. Fasteners 224 may pass through corresponding holes 222 andinto a plurality of corresponding blind holes 226 on upper surface 162of upper plate 150.

In some embodiments of pump adaptor 64′, a second inlet (through-hole)may be provided in upper plate 150 (e.g., also having a threaded innersurface). In the illustrated example, a plug is provided to seal thissecond inlet. In other examples, a second recycle passage could becoupled thereto. The second inlet and plug are optional.

The upper plate 150, lower plate 152, screen 154, supports 206,retention ring 220, and various fasteners 214, 216, 224 may be comprisedof any suitable chemically-resistant material such as 316 Stainlesssteel, titanium, surface-protected aluminum, or the like.

To assemble pump adaptor 64′ to feed pump 68′, the upper plate 150, thelower plate 152, and screen 154 may be assembled using the supports 206and fasteners 214, 216. Thereafter, the cap 120 of feed pump 68′ may beremoved enabling the upper and lower plates 150, 152 to be slid over themesh ring 124 so that keys 172, 198 align with external protrusion 138of feed pump 68′. Thereafter, the cap 120 may be replaced. (While notpreviously described, cap 120 may be secured or loosened using fastenerslocated in the circumferentially-located holes extending from outersurface 134 of cap 120.) The size of the inner diameters ID₁₅₀, ID₁₅₂may correspond with a diameter of the cylindrical mesh ring 124 (of thefeed pump 68′) sealing channel 156 to mesh ring 124—thereby defining themixing chamber 72′. Optionally, any suitable sealant may be applied tothe outer surface 140 of feed pump 68′ near the inner edge 170 (of upperplate 150) and correspondingly near the inner edge 196 (of lower plate152)—this may inhibit debris from bypassing screen 154 and secondaryscreens 188 and entering the mixing chamber 72′. When such solids enterthe mixing chamber 72′, they may accumulate on (and clog) mesh ring 124(of feed pump 68′)—thereby necessitating disassembly and internalcleaning of pump adaptor 64′. The annular retention ring 220 then may becoupled to the upper plate 150 using fasteners 224 (as shown in FIG. 6). FIGS. 6-7 also illustrate that an optional eyelet bolt 228 may bethreaded into cap 120 and serve as a strain relief for wiring 142 or asan attachment point for a retrieval device (i.e., a device that may beused to retrieve mixing portion 14′ from source 300). FIG. 6 illustratesthat an output nozzle 229 also may be coupled to the pump outlet 132.

Nozzle 229 may be coupled to passage 28 (shown in FIG. 1 ). And recyclepassage 46 (which is coupled to contaminant regulator 66) may be coupledto pump adaptor 64′. E.g., QDC feature 88 of contaminant regulator 66may be coupled to QDC feature 104 of pump adaptor 64′. Note passage 110shown in FIG. 1 may be optional, as mixing chamber 72′ is in directfluid communication with pump intake 123 of feed pump 68′. Pre-filter111′ may be assembled prior to use as well; a description follows.

Returning to FIG. 3 , pre-filter 111′ may be a bag filter that envelopesa cage 230 that is coupled to pump adaptor 64′. According to oneexample, pre-filter 111′ may comprise an elongated body 240 having ahollow region 242 therein, wherein the body 240 comprises a lip region244 at one end. The lip region 244 defines an opening 246 to thepre-filter 111′. As explained more below, the hollow region 242 may besufficiently large to envelope the cage 230 and at least a portion ofthe pump adaptor 64′. As described above, the retention ring 220 andfasteners 224 may be used to secure the pre-filter 111′ to the pumpadaptor 64′ by compressing the lip region 244 of pre-filter 111′ beneaththe retention ring 220 and using the fasteners 224 to retain the lipregion 244. In this manner, raw fluid drawn into the mixing portion 14′first passes through pre-filter 111′, then through screen 154 and/or thesecondary screens 188 (of the pump adaptor 64′), then through the meshring 124 (of feed pump 68′), and then into the pump mechanism 130.

FIG. 3 also illustrates a non-limiting example of cage 230 which mayprotect feed pump 68′ from damage. Cage 230 may comprise any suitablestructural features which permit fluid to pass therethrough and whichalso provide rigidity to a predefined interior volume 247 around body112 of feed pump 68′. In the illustration, cage 230 comprises a base 248coupled to a plurality of axially-extending stanchions 250, wherein thestanchions 250 are arranged circumferentially around the feed pump 68′and an outer peripheral region 252 of base 248. A proximal end 254 ofeach stanchion may be coupled to base 248 in the outer peripheral region252 via any suitable manner (e.g., such as fasteners (not shown)).Similarly, a distal end 256 of each stanchion 250 may abut lower surface186 of lower plate 152, being coupled to lower plate 152 via anysuitable technique (e.g., such as fasteners (not shown)).

Other cage features are also contemplated herein. E.g., while notrequired, cage 230 could have one or more transverse members which couldextend between adjacent stanchions 250.

The embodiment of mixing portion 14′ shown in FIG. 3 may be a handhelddevice in which a human user may place or throw into a body of water todraw water to membrane portion 12. Thus, mixing portion 14′ may have alength of wiring 142 and passages 28, 46. According to a non-limitingexample, the length may be 20-100 feet. These items may be coupledtogether to avoid tangling (e.g., using straps, clips, zip-ties, etc.).In at least one embodiment, the wiring 142, passage 28, and recyclepassage 46 may be formed in a common assembly; however, this is notrequired.

The following example illustrates an exemplary use of the mixing portion14′, as well as some engineering data acquired through testingdemonstrating an increase in efficiency per unit volume of raw fluid.Accordingly, the instant system particularly may be suitable for aridenvironments wherein a source 300 of fluid (FIG. 1 ) may have relativelylittle volume; of course, any size source 300 may be used.

The membrane portion 12 of portable system 10 may be on the ground,mounted on a vehicle, or on a vehicle trailer. Typically, the entiresystem 10 may be a one- or two-man lift (e.g., it may be less than 100pounds (lb.)). To use the system 10, a user may measure a concentrationof dissolved solids in source 300. According to a non-limiting example,based on this measurement, the user may select an appropriatecontaminant regulator 66 from a set of contaminant regulators 310 (FIG.12 ) (e.g., a plurality of contaminant regulators each having adifferent bleed rate parameter). E.g., each the contaminant regulators66 may be fixed bleed-off components corresponding to a uniquepredetermined bleed rate parameter. In other examples, a variablebleed-off component may be used instead. In at least one embodiment, thesystem 10 may be adapted to a military or industrial implementation andfixed bleed-off components may be more suitably robust (having fewermoving parts). Table I below illustrates that a predetermined bleed rateparameter may correspond to a concentration parameter (PPM).Accordingly, the user may select contaminant regulator 66 from set 310that corresponds with the desired bleed rate parameter. As describedabove, as concentrate fluid is recycled and returned to mixing chamber72′, if some of the concentrate fluid is not bled off, the concentrationwithin the system 10 will increase and eventually inhibit efficient (orany) operation of the system 10 (e.g. without bleed off (i.e., 0% bleedrate parameter), eventually the PPM will increase to infinity).

For purposes of explanation and not to be limiting, consider anembodiment of membrane portion 12 and mixing portion 14′ that yields 20%permeate when the bleed rate parameter is 0%. By way of example,conventional reverse osmosis systems reject (e.g., dump as waste) theremaining 80% of source 300 of fluid. By way of example only, Table Iillustrates empirical data indicating that 4% to 76% of concentratefluid may be recycled (depending on the PPM in the source 300), wherein95% to 5% is bled off, respectively. Through empirical testing of mixingportion 14′ it has been determined that as much as 90% yield of permeatefluid may be realized—e.g., as opposed to the mere 20% yield inconventional reverse osmosis systems. For example, regardless of the PPMof the source 300 of fluid, 200 gallons from fluid source 300 yielded180 gallons of permeate fluid. Per Table I, “Max Start (PPM)” refers toa maximum PPM of the raw fluid entering system 10 (and represented thehighest Total Dissolved Solids (TDS) that were introduced to the system10).

TABLE I Bleed Increase Max Percent Rate PPM to Start Recycled (%) RO (%)(PPM) Feed (%) 0 ∞ — 80% 5 464% 7,543 76% 10 275% 12,727 72% 15 211%16,588 68% 20 179% 19,553 64% 25 159% 22,013 60% 30 146% 23,973 56% 35137% 25,547 52% 40 130% 26,923 48% 45 124% 28,226 44% 50 120% 29,167 40%55 116% 30,172 36% 60 113% 30,973 32% 65 111% 31,532 28% 70 108% 32,40724% 75 107% 32,710 20% 80 105% 33,333 16% 85 103% 33,981 12% 90 102%34,314  8% 95 101% 34,653  4% 100 100% 35,000  0%

Table II illustrates empirical data demonstrating that filter flow andflow rates of system 10 are not negatively impacted based on recyclingconcentrate fluid via recycle passage 46 and in accordance with usingcontaminant regulator 66. More particularly, the turbidity of the fluidin output passage 28 (downstream of mixing chamber 72) remains lowerthan the turbidity of the source 300 over a time duration. Table II alsoillustrates that the controlled flow of recycled fluid introduced to themixing chamber 72′ with new raw fluid from source 300 does not cause theconductivity of output passage 28 to spike or exponentially increase.E.g., Table II illustrates a gradual increase in conductivity of source300 (time 30-135 minutes) and a corresponding increase in conductivityat output passage 28 over the same duration. Consequently, Table IIdemonstrates that fluid recycled from membrane apparatus 24 may bere-introduce into the mixing chamber 72′ without causing instability inthe system 10. (Note: abbreviations: “min” refers to minutes, “NTU”refers to Nephelometric Turbidity Units, “μS/cm” refers tomicro-Siemens/centimeter, “GPM” refers to gallons per minute, and “GPH”refers to gallons per hour.)

TABLE II Flow Pressure Pressure Source Output Source Output from after a1^(st) after a 2^(nd) Permeate 300 Passage 28 300 Passage 28 Feed Filter(18a) Filter (18b) Flow via Time Turbidity Turbidity ConductivityConductivity Pump 68′ (psi) in (psi) in Outlet 58 (min) (NTU) (NTU)(μS/cm) (μS/cm) (GPM) passage 30 passage 28 (GPH) 30 29.8 24.9 289 6522.5 32 34 34 45 32.2 22.8 295 666 2.5 32 34 34 60 32.4 21.6 298 681 2.532 34 33 75 32 24.1 304 695 2.5 32 34 34 90 27.7 22.5 309 709 2.5 32 3434 105 31.2 21.9 315 715 2.5 32 34 34 120 29.4 23.9 320 728 2.5 31 34 34135 29.8 25.3 326 745 2.5 31 34 34

Other embodiments of system 10 also exist. In at least one embodiment,no additional pump is used between energy recovery apparatus 22 and feedpump 68 or 68′—e.g., along recycle passage 46 to increase fluid pressurethrough contaminant regulator 66 or to mixing chamber 72 or 72′.

According to another embodiment, one or more ports 94, 96 of contaminantregulator 66 may be directed at pre-filter 111 (or 111′). In thismanner, pre-filter 111, 111′ may be sprayed and cleaned. Thus,concentrate fluid in recycle passage 46 may remove large debris andparticles adhering to an outer surface of pre-filter 111, 111′.

According to another embodiment, feed pump 68 may not be part of mixingportion 14. FIG. 13 illustrates a portable filtration system 10″ showinga membrane portion 12″ and a mixing portion 14″. Membrane portion 12″includes feed pump 68 and otherwise may be unchanged. Similarly, mixingportion 14″ may be identical to mixing portion 14 except that it doesnot include feed pump 68. In such a case, a user may place or tossmixing portion 14″ into fluid source 300 and the system 10′ mayotherwise operate similarly.

Thus, there has been described a portable filtration system thatrecycles concentrate fluid. The portable filtration system controls ableed-off of recycled fluid, increases a yield rate of permeate fluid(e.g., with respect to raw fluid intake), and minimizes the replacementor cleaning of filters therein.

Embodiments of the present disclosure have been described above. It isto be understood, however, that the disclosed embodiments are merelyexamples and other embodiments can take various and alternative forms.Further, it is contemplated that one or more embodiments may be combinedwith one another—regardless of whether such various combinations ofembodiments are explicitly illustrated in the figures or described inthe written description.

The figures are not necessarily to scale; some features could beexaggerated or minimized to show details of particular components.Therefore, specific structural and functional details disclosed hereinare not to be interpreted as limiting, but merely as a representativebasis for teaching one skilled in the art to variously employ theembodiments. In addition, relative terms such as “upper,” “lower,”“middle,” “above,” “over,” “below,” “under,” “front,” “back,” “forward,”“rearward,” “right,” “left,” and the like are not intending to belimiting; instead, such terms are used for purposes of illustration andenhancing explanation.

The term coupled may refer to a state of being directly, mechanicallycoupled or indirectly, mechanically coupled. Indirect couplings may haveintermediate parts of components between the two parts or componentssaid to be coupled. Directly coupled may refer to parts or componentsfastened, attached, or otherwise mated to one another withoutintermediate components.

What is claimed is:
 1. A portable filtration system, comprising: amixing portion, comprising: a pump adaptor, comprising: an upper plate;a lower plate; and a screen axially extending between the upper andlower plates, wherein the upper plate, the lower plate, and the screendefine a channel of a mixing chamber; and a contaminant regulator,comprising a housing having an input opening, an output opening, athrough-passage extending between the input and output openings, and atleast one bleed passage extending from the through-passage, wherein thecontaminant regulator is coupled to the upper plate, wherein thethrough-passage is in fluid communication with the mixing chamber,wherein the at least one bleed passage is not in fluid communicationwith the mixing chamber.
 2. The portable filtration system of claim 1,wherein the lower plate comprises a plurality of apertures, wherein asecondary screen covers each of the plurality of apertures.
 3. Theportable filtration system of claim 1, further comprising an axiallyextending cage coupled to the pump adaptor defining an interior volume,wherein the mixing portion further comprises a pre-filter that comprisesa bag filter enveloping the cage and coupled to the pump adaptor.
 4. Theportable filtration system of claim 3, wherein the pump adaptorcomprises a retention ring, wherein a lip region of the bag filteroverlays an upper surface of the upper plate and the retention ringoverlays the lip region thereby enclosing the screen and the lower platewithin the bag filter.
 5. The portable filtration system of claim 3,wherein the upper plate has an inner diameter defined by an inner edge,wherein the inner edge comprises a key that inhibits rotation of theupper plate when the upper plate is coupled to a feed pump having anelongated shape that corresponds with a shape of the inner edge.
 6. Theportable filtration system of claim 5, wherein the mixing portionfurther comprises the feed pump, wherein the feed pump has a body and ahead extending from the body, wherein the head at least partiallyextends between the upper and lower plates, wherein an outer surface ofthe head defines a fourth wall of the mixing chamber, wherein theinterior volume of the cage is sized to receive the body of the feedpump.
 7. The portable filtration system of claim 6, wherein the pumpadaptor comprises a retention ring, wherein a lip region of the bagfilter overlays an upper surface of the upper plate and the retentionring overlays the lip region thereby enclosing the screen and the lowerplate within the bag filter.
 8. The portable filtration system of claim6, wherein the mixing portion further comprises an output passage thatextends from the feed pump and a recycle passage that extends from thecontaminant regulator.
 9. The portable filtration system of claim 8,further comprising a membrane portion that comprises: a filter; a boostpump; a membrane apparatus comprising a permeate chamber and aconcentrate chamber segregated by a membrane, wherein the membraneapparatus is in fluid communication with the feed pump via the filter,the boost pump, and the output passage; a concentrate passage; and anenergy recovery apparatus, wherein the concentrate passage carrieshigh-pressure concentrate fluid from the concentrate chamber to theenergy recovery apparatus, wherein the recycle passage carrieslow-pressure concentrate fluid from the energy recovery apparatus to themixing chamber via the contaminant regulator.
 10. The portablefiltration system of claim 9, wherein the contaminant regulatorcomprises a quick-disconnect feature facilitating quick-disconnectionfrom the pump adaptor.
 11. The portable filtration system of claim 10,wherein the mixing portion further comprises a plurality of contaminantregulators each having a different predetermined bleed rate parameter,wherein each of the plurality of contaminant regulators comprises aquick-disconnect feature.
 12. The portable filtration system of claim 9,wherein a line pressure of the recycle passage at an outlet of theenergy recovery apparatus corresponds with a line pressure of therecycle passage at the input opening of the contaminant regulator. 13.The portable filtration system of claim 1, wherein the contaminantregulator further comprises one or more ports which facilitate fluidcommunication between the through-passage and an environment of themixing portion.
 14. A portable filtration system, comprising: a mixingportion, comprising: a feed pump having an elongated shape andcomprising a body and a head extending from the body; a pump adaptor,comprising: an upper plate; a lower plate, a screen axially extendingbetween the upper and lower plates, wherein the upper plate, the lowerplate, the screen, and the head of the feed pump define a mixingchamber; and a contaminant regulator comprising a through-passagecoupled to the upper plate, wherein the through-passage is in fluidcommunication with the mixing chamber; an output passage that is influid communication with the feed pump; and a recycle passage that is influid communication with the through-passage of the contaminantregulator; and a membrane portion, comprising: a filter; a boost pump; amembrane apparatus comprising a permeate chamber and a concentratechamber segregated by a membrane, wherein the membrane apparatus is influid communication with the feed pump via the filter, the boost pump,and the output passage; a concentrate passage; and an energy recoveryapparatus, wherein the concentrate passage carries high-pressureconcentrate fluid from the concentrate chamber to the energy recoverydevice, wherein the recycle passage carries low-pressure concentratefluid to the mixing chamber via the contaminant regulator.
 15. Theportable filtration system of claim 14, wherein the lower platecomprises a plurality of apertures, wherein a secondary screen coverseach of the plurality of apertures.
 16. The portable filtration systemof claim 14, further comprising an axially extending cage coupled to thepump adaptor defining an interior volume, wherein the mixing portionfurther comprises a pre-filter that comprises a bag filter envelopingthe cage and coupled to the pump adaptor.
 17. The portable filtrationsystem of claim 16, wherein the pump adaptor comprises a retention ring,wherein a lip region of the bag filter overlays an upper surface of theupper plate and the retention ring overlays the lip region therebyenclosing the screen and the lower plate within the bag filter.
 18. Theportable filtration system of claim 14, wherein the contaminantregulator comprises a quick-disconnect feature facilitatingquick-disconnection from the pump adaptor.
 19. The portable filtrationsystem of claim 14, wherein the mixing portion further comprises aplurality of contaminant regulators each having a differentpredetermined bleed rate parameter, wherein each of the plurality ofcontaminant regulators comprises a quick-disconnect feature.
 20. Aportable filtration system, comprising: a pump adaptor, comprising amixing chamber, an inlet for receiving raw fluid, an inlet for receivingrecycled fluid, and an outlet; a feed pump in fluid communication withthe outlet of the pump adaptor; a boost pump in fluid communication withthe feed pump; an energy-recovery means in fluid communication with theboost pump; and a membrane apparatus comprising a concentrate chamberand a permeate chamber, wherein the concentrate chamber is in fluidcommunication with the energy recovery means via a concentrate passage,wherein the energy-recovery means is in fluid communication with thepump adaptor via a recycle passage.
 21. A portable filtration system,comprising: a mixing portion, comprising: a pump adaptor, comprising: anupper plate; a lower plate; and a screen axially extending between theupper and lower plates, wherein the upper plate, the lower plate, andthe screen define a channel of a mixing chamber; and a contaminantregulator, comprising a through-passage coupled to the upper plate,wherein the through-passage is in fluid communication with the mixingchamber, wherein the upper plate has an inner diameter defined by aninner edge, wherein the inner edge comprises a key that inhibitsrotation of the upper plate when the upper plate is coupled to a feedpump having an elongated shape that corresponds with a shape of theinner edge.